Calls to this function can be simplified by this
other function (see Section
35.9.11)

proisagg

bool

Function is an aggregate function

proiswindow

bool

Function is a window function

prosecdef

bool

Function is a security definer (i.e., a "setuid" function)

proleakproof

bool

The function has no side effects. No information
about the arguments is conveyed except via the return
value. Any function that might throw an error depending
on the values of its arguments is not leak-proof.

proisstrict

bool

Function returns null if any call argument is null.
In that case the function won't actually be called at
all. Functions that are not "strict" must be prepared to handle null
inputs.

proretset

bool

Function returns a set (i.e., multiple values of the
specified data type)

provolatile

char

provolatile tells
whether the function's result depends only on its input
arguments, or is affected by outside factors. It is
i for "immutable" functions, which always
deliver the same result for the same inputs. It is
s for "stable" functions, whose results (for
fixed inputs) do not change within a scan. It is
v for "volatile" functions, whose results might
change at any time. (Use v also
for functions with side-effects, so that calls to them
cannot get optimized away.)

An array with the data types of the function
arguments. This includes all arguments (including
OUT and INOUT arguments); however, if all the
arguments are IN arguments, this
field will be null. Note that subscripting is 1-based,
whereas for historical reasons proargtypes is subscripted from
0.

proargmodes

char[]

An array with the modes of the function arguments,
encoded as i for IN arguments, o
for OUT arguments, b for INOUT
arguments, v for VARIADIC arguments, t for TABLE
arguments. If all the arguments are IN arguments, this field will be null.
Note that subscripts correspond to positions of
proallargtypes not
proargtypes.

proargnames

text[]

An array with the names of the function arguments.
Arguments without a name are set to empty strings in the
array. If none of the arguments have a name, this field
will be null. Note that subscripts correspond to
positions of proallargtypes
not proargtypes.

proargdefaults

pg_node_tree

Expression trees (in nodeToString() representation) for
default values. This is a list with pronargdefaults elements,
corresponding to the last Ninput arguments (i.e., the
last Nproargtypes positions). If none of the
arguments have defaults, this field will be null.

prosrc

text

This tells the function handler how to invoke the
function. It might be the actual source code of the
function for interpreted languages, a link symbol, a file
name, or just about anything else, depending on the
implementation language/call convention.

probin

text

Additional information about how to invoke the
function. Again, the interpretation is
language-specific.

For compiled functions, both built-in and dynamically loaded,
prosrc contains the function's
C-language name (link symbol). For all other currently-known
language types, prosrc contains the
function's source text. probin is
unused except for dynamically-loaded C functions, for which it
gives the name of the shared library file containing the
function.